Natural interior lighting is desirable in commercial buildings for a variety of reasons including, among others, energy use efficiency and enhancement of the workplace environment. A variety of skylight systems thus are known and used. For example, it has been common practice to install individual skylight panels on a pitched roof at points below the roof ridge. Another skylight arrangement includes a series of adjacent, light transmitting panels that bridge the ridge of a double pitched roof and extend along the ridge.
Any skylight system must, of course, be well adapted to installation in a building roof structure. A roof structure of increasingly common use is the so-called standing seam roof, in which elongated sheet metal roof panels, up to 150 feet in length for example, extend from the building eaves to the roof ridge, and are joined to the adjacent roof panels at formed, upstanding seams that likewise run from the eaves to the ridge.
In a standing seam roof installation, the roof panels typically are immovably secured to the roof frame at the eaves, and further secured with sliding clips positioned at intervals along the length of the standing seams. The sliding freedom of the clips leaves the roof panels free to move for accommodation of thermal expansion and contraction, which can be substantial owing to the length of the roof panels. Since the roof panels are fixed to the roof frame at the eaves, the largest roof panel movement occurs at the roof ridge, and this complicates ridge skylight installation. Among the problems associated with skylight systems generally, including ridge skylights, are leakage and condensation, curb or flashing fit, safety, and positive termination of the blanket insulation that commonly underlies the roof panels.
Among the skylight systems represented in the prior art are the following: Russian Patents SU 1534161 and SU 1724830, U.S. Pat. Nos. 4,614,067, 1,872,868, 1,772,068, German Patent 292551, and Japanese Patent 6-42096. U.S. Pat. No. 5,212,913 discloses a roof ridge fitting, although not a skylight.